The verdict comes over a year after Hussein brutally stabbed and killed two sisters in London as part of a "blood contract with a demon" to win the lottery.
The teenage boy asked his current girlfriend to lure the victim by promising him sex and told the other teenage girl that he needed help to fight someone who had raped a friend.
Fatinah Hossain, 25, was in a sexual relationship with the victim for several months and even tried to pay him to "drop the charges" following her arrest.
Michael Campbell's face and body is almost entirely covered with tattoos that include a pentagram, Celtic knots as well as a pit bull and a large polka dot bowtie.